The present invention relates to hair styling compositions and a method of enhancing the performance of hair fixative resins. More particularly, the present invention relates to a method of improving the stiffness performance of hair fixative resins. In a preferred embodiment, the present invention also relates to aqueous hair styling compositions containing low (80 weight percent or less) volatile organic compound (VOC) concentrations.
Hair styling products, such as hair sprays, styling gels, spray gels and mousses are used on hair to hold the hair in a particular shape or configuration. The hair styling products, when applied, form a thin film or weld of resin on the hair, most efficiently in the seam between adjacent hair fibers or at a point where the fibers cross one another, and, as a result, hold the hair in a particular shape or configuration.
Hair styling products can be applied to the hair in several ways. For example, the hair styling product may be applied by a spray using a propellant (such as in an aerosol hair styling product), using a hand pump, or, in the case of a gel, applied to the hair by hand directly. Hair styling products typically contain one or more VOC. VOC contribute to ground level air pollution in the presence of sunlight and air, and are volatile under ambient conditions.
Legislation in New York, California and other states mandates that the amount of VOC formulated into hair styling products that are sprayed, such as aerosol and pump hair sprays, must not exceed 80 weight percent (%) in the product. By June 1999, the amount of VOC in hair styling products that are sprayed must be reduced to 55% in California. Other states have enacted similar legislation mandating the reduction of VOC in hair styling products that are sprayed. Present hair styling products in the United States that are sprayed typically have VOC levels of 80% or less. Such VOC include, for example, ethanol, dimethyl ether and hydrocarbons; the most likely replacement for VOC is water.
In order for a resin to be suitable in a hair spray composition it must exhibit a combination of desirable performance attributes. These include, but are not limited to, compatibility of the resin in the hair spray composition, satisfactory high humidity curl retention, satisfactory stiffness on the hair, low tackiness after spraying on the hair, short dry times, no visible residue on the hair, easy shampoo removability, and easy sprayability resulting in a uniform mist of spray delivered to the hair.
Hair fixative resins available in the marketplace today, for example, Amphomer LV-71 (octylacrylamide/acrylates/butylaminoethyl methacrylate copolymer) and Resyn 28-2930 (vinylacetate/crotonic acid/vinylneodecanoate copolymer) satisfy many of these performance attributes, but only in hair spray compositions containing a limited amount of formulated water, for example, less than 15%, such as usually found in 80% VOC hair spray compositions (Amphomer and Resyn are trademarks of the National Starch and Chemical Company). These resins are compatible in the hair spray composition, and give a firm, stiff feel to the hair, but are deficient in either residue properties or curl retention. In particular, these resins are unsuitable in 55% VOC hair spray compositions (containing significant amounts of formulated water) due to poor spray properties from high viscosity, incompatibility in the hair spray composition, or having extended dry times.
U.S. Pat. No. 4,196,190 discloses acrylic hair fixative resins containing 10-30% of an alkyl acrylate, 41-60% of methyl methacrylate, 5-20% of hydroxyethyl methaerylate and 10-30% of methacrylic acid. Although disclosing acrylic hair fixative resins that are compatible in 55% VOC hair spray compositions containing large amounts of formulated water, give excellent high humidity curl retention, excellent shampoo removability, short dry times, low or no tackiness, but deliver a soft, natural feel to the hair, this reference does not disclose or suggest how to improve the stiffness of the resin on the hair. Although a soft feel to the hair is desirable for those formulators targeting a more manageable, natural feeling hair style, a significant portion of the population prefers a stiff, firm hold to the hair.
U.S. Pat. No. 5,658,558, although disclosing how to improve the performance of acrylic resins in low-VOC systems, also does not disclose how to improve hair stiffness.
The present invention seeks to improve upon the prior art hair fixative resin technology by using selected polymers as hair fixative resins that are compatible in hair fixative compositions containing large amounts of water, for example, 55% VOC compositions, while retaining other beneficial hair fixative properties, such as (i) low tackiness, (ii) short dry times, (iii) easy shampoo removability, (iv) excellent high humidity curl retention, (v) easy sprayability, and in addition, delivering a stiff, firm hold to the hair, rather than a soft feel to the hair.